Preparation of beta, beta&#39;-bis (alkylmercapto) diethyi, ether



Patented Sept. 29, 1953 UNITED TES- PATENT ore-ice PREPARATION or. as-Brsl ALKimMEn A I )D E rE' JHEE Edward L. Doerr, Dayton, h io ass ignor to Mon santo=..Chemical .Company, 'St. Louis; M0; at corporation of :.Delawarel No nrawing Application February 3, 1949,

SerialNo. 74 4. 5

6' Claims..,.. (01. 260 -609 This inventionrelatesto-a novel method of preparing water insoluble-derivatives of alkyl mer captans lvforespecifically-the invention relates to gathers.v prepared by the dehydration of alkylmercaptoethanols The primarypurpose of this invention is toproyide useful derivatives from alkyl mercaptans; which'are abundantly available at low cost.- A

further purpose; of this invention is to provide a v new chemical rea'ction valuable in the synthesis of yarious organic compounds, particularly dithia+alkyl ethers.

The method of preparing ethers by the dehy dration of alcohols with sulfuric acid is well known, but'this reaction ordinarily requires the use of elevated temperatureafor example 1&0

C. to 160C. -"Furthermore, when longchain alkyl alcphols'are dehydrated themethod is not -ap plicable; because of dehydration toproduce olefins. Accordingly, the longchainethers are usuallyprepared by the Williamson ether synthesis. It has been discovered thata different phenomenon isinvolved in'the dehydration of fi-(alkylmercapto) ethanols.-

found that the fi-(alkylmercapto) peratures less than 110;

cation;catalysts. Suitable acidic catalysts for converting the alkyl mercaptoethanols to the corresponding ethers are, the acids conventionally used in esterification procedures and-the salts of these acids capable of generatin the acid in site during the course of the reaction. The re-; action may lee-performed withsulfuric acid; phosa phoric acid; phosphorus pentoxide;sulfonic acidg sulfur trioxide, toluene sulfonic acid; benzene sul-i fonicacid; hydrogen fluoride; boron trifluori'de; zinc chloride, aluminum chloride, stannic chloride, sodium bisulfate, zinc sulfate, boron trifluoride complexes both organic and inorganic, and other acids and salts having acidic reactions.

Compounds of particular interest are those made from the 18-(alkylmercapto) ethanols prepared by the condensation of ethylene oxide with any alkyl mercaptan wherein the alkyl group has from four to eighteen carbon atoms. The alkyl radical may be primary, secondary or tertiary. The mercaptoethanols are prepared by charging a suitable reactor with the mercaptan and bubbling ethylene oxide through it in the presence of solid alkali metal hydroxide. The reaction, which may be followed by means of periodic ash h uld-b in errupted .a ...s 9n. ss chiqmctri pr portion-cf thegi rlcn ide...

has been. absorbed...

The alkyl mercaptoethanols are thereafter con- -verted to the corresponding.e,e'-bis(alkylmercaptors diethy-l, others contacting ,them with the acidicpatalylsts. lfldesired the reaction may i be conducted in the presencee i an inertsolyent or diluent for examplev toluene. dioxane,,.carbon -=tetrach1oride The .reaction willuoften proceedreadily atv room.tempqrflilmes and,.since the ,re action is exothermic, contin ous, or periodic cool:

ing'. may, be. necessary.to maintain the v reaction undercontrol. Generally iti is.. desirable to, con; 'duct. the reaction. with ,the reaction. ,iiaslg immersed in an ice bath, and combining the T61.

agents at a slow enough rate to permit the maintenance of the reaction temperature within the prescribed; limits; v The temperature used in the practiceof} the: reactiqnv will depend; upon the i particular; nature ofethe catalyst ,used, very-ac;

tire, catalysts .s uch. as {sulfur triox'ida..10(),percent il r e-aqi renslrshlvm el tb a e mit ,6; trwm em atrresan l w mi m-L perature, dilute acids and acid salts regmiring temperatures up to 100? C. The reaction mass may thereafter be processed by dissolving it in h blr neu ralizi i ew xc saeqid M me s 9 anic ltsa y fil ationnsit erea t rip eciei. the alcohol solution. r.

thet la inae e ifi aex mplesrcm e f A 3-necked, round-bottom flask was provided with a. thermometer, and efficient rotary stirring device and a, dropping funnel. The vessel was charged with 109.2 grams of fl-(n-decylmercapto) ethanol which was prepared by condensing equimolecular quantities of n-decyl mercaptan and ethylene oxide, and also with 200 grams of dry carbon tetrachloride. The solution was cooled to C. and '75 grams of 100 percent sulfuric acid was added dropwise at a rate which permitted the maintenance of a temperature between 25 and C. by immersion of the reaction vessel in an ice bath. The resulting thick reaction mass was diluted with water, dissolved in ethanol, and neutralized with percent sodium sqdiumh dr d s w:

. mraqlmd ia e i e u za ;p a cizers; termedia es;f re sari Neme p eo l we hydroxide solution. Solid sodium sulfate was precipitated and was removed by filtration of the hot ethanol solution which upon cooling produced a solid crystalline water-insoluble substance having a melting point of 43-44 C. This product was identified as fi,B-bis(n-decylmercapto) diethyl ether.

Example 2 The procedure of Example 1 was repeated except that B-(n-dodecylmercapto) ethanol was used. The white crystalline product obtained had a melting point of 5456 C. and was identified s fi,fi'bis(n-dodecylmercapto) diethyl ether.

Example 3 The procedure of the preceding example was repeated except that 71.3 grams of chlorosulfonic acid was used instead of sulfuric acid, and the reaction was conducted between and C. The water insoluble product recovered and recrystallized from ethanol solution was identified as p,p-bis(n-dodecylmercapto) diethyl ether.

Example 4 A l-liter, round-bottom flask provided with a reflux condenser and a Stark and Dean moisture trap was charged with 500 grams of dry toluene and 190.3 grams of fi-(n-octylmercapto) ethanol and 1 ml. of 96 percent sulfuric acid. The reaction mass was refluxed for three hours at 110 C., at which time approximately nine grams of water had been collected. The product was separated as an oil at room temperature and identified as id-bis(n-octylmercapto) diethyl ether.

Example 5 Using the apparatus identical to that used in Example 1, 58.7 grams of ii-(tertiary hexadecylmercapto) ethanol was reacted with 30 grams of 100 percent sulfuric acid, using dioxane as the diluent. The water insoluble product separated was identified as Alf-bis(t-hexadecylmercapto) diethyl ether.

Example 6 A 1-1iter, 3-necked flask was provided with a. mechanical stirring device and a liquid dropping funnel. The flask was charged with 112 grams of p-(n-octylmercapto) ethanol. The flask was cooled to a temperature of 15 C. and 500 ml. of liquid sulfur dioxide was added thereto. The dropping funnel was then charged with 52 grams of liquid sulfur trioxide. While maintaining the flask at a temperature of below 10 C. the sulfur trioxide was added dropwise over a period of twenty minutes. After the completion of the reaction the sulfur dioxide was permitted to boil off slowly. After all the sulfur dioxide had been evolved 300 ml. of water was added. The aqueous slurry was then extracted with diethyl ether and the product recovered by evaporation of the ether. The resulting compound was identified as /3,/3-bis(n-octylmercapto) diethyl ether.

The invention is defined by the following claims.

I claim:

1. A method of preparing p,fi-bis(alkylmercapto) diethyl ether which comprises contacting in liquid phase B-(alkylmercapto) ethanol, wherein the alkyl radical has from four to eighteen carbon atoms, with a catalyst selected from the group consisting of acidic esterification catalysts and acid reacting salts at a temperature less than about C. and separating the resultant water-insoluble product.

2. A method of preparing p,;8-bis(alkylmercapto) diethyl ether which comprises contacting in liquid phase p-(alkylmercapto) ethanol, wherein the alkyl radical has from four to eighteen carbon atoms, with an oxygen-containing sulfur acid at a temperature less than about 110 C. and separating the resultant ether.

3. A method of preparing p,B-bis(a1kylmercapto) diethyl ether which comprises contacting in liquid phase fi-(alkylmercapto) ethanol with liquid sulfur trioxide in a liquid sulfur dioxide medium at a temperature less than about 110 C. and separating the resulting ether.

4. A method of preparing p,p-bis(t-hexadecylmercapto) diethyl ether which comprises contacting in liquid phase fl-(t-hexadecylmercapto) ethanol with an acidic esterification catalyst at a temperature less than about 110 C. and separating the resulting ether.

5. A method of preparing [3,,8'bis(n-octylmercapto) diethyl ether which comprises contacting in liquid phase fi-(n-octylmercapto) ethanol with an acidic esterification catalyst at a temperature less than about 110 C. and separating the resulting ether.

6. A method of preparing B,p-bis(n-dodecylmercapto) diethyl ether which comprises contacting in liquid phase ;8(ndodecylmercapto) ethanol ether which comprises contacting in liquid phase p-(n-dodecylmercapto) ethanol with an acidic esterification catalyst at a temperature less than about 110 C. and separating the resulting ether.

EDWARD L. DOERR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,326,483 Moran Aug. 10, 1943 2,402,878 Doumani June 25, 1946 2,492,984 Grosse et a1 Jan. 3, 1950 2,570,050 Eby Oct. 2, 1951 

1. A METHOD OF PREPARING B,B''-BIS(ALKYLMERCAPTO) DIETHYL ETHER WHICH COMPRISES CONTACTING IN LIQUID PHASE B-(ALKYLMERCAPTO) ETHANOL, WHEREIN THE ALKYL RADICAL HAS FROM FOUR TO EIGHTEEN CARBON ATOMS, WITH A CATALYST SELECTED FROM THE GROUP CONSISTING OF ACIDIC ESTERIFICATION CATALYST AND ACID REACTING SALTS AT A TEMPERATURE LESS THAN ABOUT 110* C. AND SEPARATING THE RESULTING WATER-INSOLUBLE PRODUCT. 